CNN - Remember that incident back in April, when a passenger was dragged off a United Airlines flight?
Aviation officials in Chicago conducted an investigation and announced Tuesday the incident was "improperly escalated."
As a result, two of the police officers involved were fired. Two more officers have been suspended.
The investigation also shows that certain facts about the incident were deliberately removed from an employee report.
The man dragged off the plane, Dr. David Dow, has reached a settlement with United Airlines.
Dow lost two teeth, had a broken nose and suffered a concussion during the incident.